At 40,000 feet, the Time Up Cabin (TUC) is approximately?

• A. 15-20 Seconds
• B. 30 Seconds to 1 Minute
• C. 1-2 Minutes
• D. 5-10 Seconds

Answer: (A)

Time Up Cabin is about the time you have to remain conscious after a sudden loss of cabin pressure without supplemental oxygen. At 40,000 feet, the brain becomes hypoxic incredibly fast, so the window to act is very short. About 15–20 seconds is the typical estimate for when consciousness would be compromised if you’re not wearing oxygen, which is why this range is the best answer. This emphasizes the urgency: pilots and cabin crew must don oxygen and begin descent promptly to restore breathable air. In contrast, longer times would imply you could delay action without immediate risk, which isn’t the case here. Remember, while the aircraft’s oxygen system provides sustained supply once in use, the critical factor at altitude is how quickly you lose consciousness without oxygen in the first moments.